1. Field Of The Invention
This invention relates to a side panel clamp mechanism adapted to grip an edge area of a metal plate or other workpiece so that the plate can be moved from place to place or manipulated into or out of a machining mechanism, such as a stamping press. The improved gripper mechanism can be carried on a robotic arm or other transfer device designed to move the gripper mechanism bodily from place to place.
2. Description Of The Prior Art
Various other types of plate gripper mechanisms are known. U.S. Pat. No. 4,448,056 to Baba shows a plate gripper mechanism wherein a fluid cylinder 130 is connected to a cam mechanism 116 for operating a movable jaw 104 between an unclamped position and a clamped position engaged with a workpiece W. The mechanism has a relatively long dimension along the axis of the cylinder 130. It is, therefore, difficult for this mechanism to move into or out of small clearance spaces.
U.S. Pat. No. 3,497,255 to Sindelar shows a gripper mechanism for gripping a workpiece W. The mechanism includes a fluid cylinder 14 having a slidable member 17 linked to a jaw 28 for gripment of the workpiece W. This mechanism is somewhat similar to the mechanism in U.S. Pat. No. 4,448,056 in that overall length of the mechanism is relatively great in a direction parallel to the axis of the fluid cylinder.
U.S. Pat. No. 4,752,094 to Tabeau shows a robotic gripping device wherein a piston 19 moves within a fluid cylinder to rotate a shaft 23 via a toothed rack 20. A work gripment jaw 42 is carried on the shaft. The mechanism shown in this patent utilizes a specially designed fluid cylinder actuator, which would be fairly expensive if produced in small volume quantities.
The Danly Machine Corporation of Chicago, Ill. manufactures a plate gripper mechanism wherein an air cylinder is connected to the shaft of a swingable jaw member via a pin-slot connection. The piston rod of the air cylinder is connected to a linear guide having two spiral slots in its inner surface. A rotary shaft is disposed within the linear guide so that a transverse pin extends from the shaft into two spiral slots. As the piston moves in the air cylinder the spiral slots exert cam actions on the end areas of the transverse pin to rotate the shaft around its axis, thereby producing a swinging motion of the associated jaw. The mechanism has a relatively long length in the direction of the rotary shaft. Also, the mechanism utilizes special castings which would be relatively expensive when produced in small volume quantities. This type of gripper mechanism provides limited output and is subject to degradation of the output force due to eventual wear of the spiral slots in the shaft.